I bought this lens on June 28, 2018 and took it with me on a cruise to Alaska the next day. The pictures that I shot with this lens were incredibly sharp and the colors were true to life. The image quality is so good that I used this lens most of the time.
I previously owned version 1 of this lens but sold it when I purchased the f/2.8 version. While the f/2.8 is a fabulous lens, it is quite heavy and I found that I wasn't taking my camera along with me as much as I used to, or wanted to. I have been planning to purchase another f/4 and when the version II came out I bit the bullet and did it. I am so happy I did!! I love the lens, it is incredibly sharp and so much lighter than the f/2.8. The f/4 is suitable for most of what I shoot and its ease of use (for my old arthritic wrists and thumbs) is bringing joy back to my photography. I will keep the f/2.8 for use with a tripod, but most of my everyday shooting will happily be with the f/4.
I received this lens in the mail, and within one hour was on my way to a sports event. I attached the lens to the camera, read two paragraphs on operation and began using the lens. Wow !! Great photos. Great quality. Super colors.